Fluorescence Definition and 65 Threads

  1. W

    Fluorescence and Raman spectroscopy

    I'm currently working on a lab that is exploring the Raman effect. One of the suggested exercises was to record the raman spectrum (from a mercury lamp through CCl4) around the rayleigh peaks at 435.8 nm and 404.7 nm. For the former, my results were fairly consistent with what I expected in that...
  2. K

    Quantum-Dot Fluorescence - Hypothetical Semiconductor

    Homework Statement Consider a hypothetical semiconductor with band gap 1eV, Relative electron mass is 0.05 and relative hole mass is 0.5. In a cube-shaped quantum dot of this material with side length L = 3nm, what is the energy associated with a transition from (2 1 1) electron state to...
  3. S

    Deconvolution IRF from fluorescence decay curves

    Hi There, I have been working on fluorescence decays of the fluorophores whose lifetimes are comparable to the instrument response function(IRF) of my device. The technique I use is based on Time-correlated single photon Counting(TCSPC). I have been fitting the decay curves using...
  4. M

    What is the physical explanation for the red color in chlorophyll fluorescence?

    Homework Statement I am doing some research for a lesson pertaining to the fluorescence of chlorophyll. When chlorophyll has been extracted from plant leaves using acetone, the solution will glow a bright red when exposed to UV light. My question is: what is the physical cause for...
  5. T

    Is it Reasonable to Measure Fluorescence with Single Molecule in 1 Second?

    Hi, I'm doing some calculations on fluorescence and I'm a little stuck on statistics. Let's say I need to measure 20 seconds to collect 10000 photons from a single molecule. Then I can say well I want to measure at most 1 second and therefore I need 20 molecules in order to collect 10000...
  6. M

    Derivation of equation for Phase-modulation fluorescence

    Hello there, I'm going through the derivation for the equations relating to frequency-domain lifetime measurements for fluorescent samples. This is a technique whereby a sinusoidally-modulated light source excites a fluorescent sample, and the fluorescence lifetime of the sample, \tau is...
  7. DaTario

    Difference between fluorescence and phorforescence

    I all, I am afraid of abusing the dictionary now, but by fluorescence I mean excitation and immediate emission. By phosforescence I means excitation and after a randomic time that can be of the order of minutes, the atom emits. I woud like to confirm if the names are correct and if there is...
  8. A

    Raman Effect and Fluorescence: Understanding the Differences and Mechanisms

    Homework Statement I understand that in the fluorescence, the incident photon is absorbed by the molecule, and the molecule while returning to its original ground level releases lesser energy. Similarly, in Raman effect also a photon is incident on a liquid molecule. In stokes' lines the...
  9. Y

    X-ray Fluorescence angle question.

    First of all, I'm not the one doing this experiment. I've just finished my first year in college and I'm sort of just helping all the upper-level with their research and whatnot. So my knowledge is very limited. With that being said, one of those student is doing X-ray Fluorescence. He was...
  10. S

    X-ray spectroscopy in labs studying Fluorescence

    I did a bit of x-ray spectroscopy in labs studying Fluorescence of some different elements. I was just wondering whether or not flourescence occurs in all elements? I'm sure I've read people talking about 'flourescecnt materials' or something like that. I can't think of any reason why it...
  11. B

    Understanding Fluorescence and pH Sensitivity of Fluorescein Molecule

    Hi, I have a quick question on fluorescence. I have fluorescein molecule. Its absorbance is pH sensitive. However, I want to know if 1. It emits fluorescence. 2. the fluorescence intensity pH sensitive I know for sure it emits fluorescence. I see, what I believe to be an emission...
  12. Loren Booda

    Can Noble Gases Be Combined for More Vibrant Colors?

    The noble gases when electrically stimulated emit different visible wavelengths. Can they be combined for a greater variety of coloration?
  13. B

    A question about biological molecule's fluorescence

    many biological molecule can emit fluorescence. but is the quantum field of these molecules large? can u give me some examples that the molecule emits strong fluorescence, such as beta-carotene? for this field ,i know little. thank u
  14. R

    What is fluorescence and how does it arise?

    What is fluorescence and how does it arise? Is it just a spontneous de-excitation after the electron in the molecule (protein) has been excited. This is a 6 mark question in last years Chemistry-2 exam and i don't really know how to go about answering it. Any suggestions?
  15. R

    What is fluorescence and how does it arise?

    What is fluorescence and how does it arise? Is it just a spontneous de-excitation after the electron in the molecule (protein) has been excited. This is a 6 mark question in last years Chemistry-2 exam and i don't really know how to go about answering it. Any suggestions?
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